Lab Report

Water Testing Lab

June 25, 2013

Julia, Clemmy, Kourosh

Dr. Forman

Purpose: The purpose of this experiment was to test for the presence of iron and calcium cations as well as chloride and sulfate anions.

Background/Significance: Through the process of testing water samples in order to discover cations and anions in the samples, we approached new, intriguing conclusions that also led us to classify qualitative and quantitative data within each procedure.

Abstract: After completing these experiments, I learned the importance of being cautious and careful in order to obtain the correct results. I also tested for the presence of cations and anions and observed in a way that would be efficient in the long run. My quantitative and qualitative data was successful and I learned many important lessons from this lab.

Procedure:

Calcium Ion (Ca²⁺) Test

1.     Place 20 drops of each sample (distilled water, reference, unknown, tap water, natural water) in a well plate

2.     Add 3 drops of sodium carbonate to each sample and record your observations

3.     Discard the contents and rinse the well plate

Iron (III) Ion (Fe³⁺) Test

1.     Place 20 drops of each sample (distilled water, reference, unknown, tap water, natural water) in a well plate

2.     Add 2 drops of potassium thiocyanate to each sample and record your observations

3.     Discard the contents and rinse the well plate

Chloride Ion (CI^-) Test

1.     Place 20 drops of each sample (distilled water, reference, unknown, tap water, natural water) in a well plate

2.     Add 3 drops of silver nitrate to each sample and record your observations

3.     Discard the contents and rinse the well plate

Sulfate Ion (SO₄^2-) Test

1.     Place 20 drops of each sample (distilled water, reference, unknown, tap water, natural water) in a well plate

2.     Add 3 drops of bacterium chloride to each sample and record your observations

3.     Discard the contents and rinse the well plate

Results:

Calcium Ion (Ca²⁺) Test

Solutions	Observations	Results
Reference:	Precipitate, cloudy	Yes
Control:	Nothing, clear	No
Tap water:	Nothing, clear	No
Natural (ocean) water:	Slightly cloudy	Yes
Distilled (blank) water:	Nothing, clear	No

Iron (III) Ion (Fe³⁺) Test

Solutions	Observations	Results
Reference:	Dark red	Yes
Control:	Light yellow	Yes
Tap water:	Nothing, clear	No
Natural (ocean) water:	Nothing, clear	No
Distilled (blank) water:	Nothing, clear	No

Chloride Ion (CI^-) Test

Solutions	Observations	Results
Reference:	White	Yes
Control:	Light yellow	Yes
Tap water:	Nothing, clear	No
Natural (ocean) water:	White, slightly cloudy	Yes
Distilled (blank) water:	Nothing, clear	No

Sulfate Ion (SO₄^2-) Test

Solutions	Observations	Results
Reference:	Yellow with tiny red dots	Yes
Control:	Murky, white, cloudy	Yes
Tap water:	Nothing, clear	No
Natural (ocean) water:	White, grey, cloudy	Yes
Distilled (blank) water:	Nothing, clear	No

Together as a group, we all worked very hard in order to obtain successful results.  We were all very organized and cooperated extremely well with one another. We did this by communicating and taking turns dropping different substances into the well plate. Although at first we were a little bit confused on what to do because of the numerous liquids we were given, together we re-read the procedures and followed them step by step. Overall, this was a very successful experiment and taught us all science skills as well as life skills. 

Overall class results: 

These results are important because it lets us compare each others work. It is also important to group the entire classes data together because it lets us check our work to see how accurate our experiments were. Opposed to establishing facts on one groups experiments, the graph allowed us to be able to study the data collected by our entire class. Overall, our we all developed close to the same results. 

1.    A reference solution and a blank were used in each test so you have something you can compare other samples to.

2.     If your well plate or pipette is contaminated, incorrect color changes might occur, precipitates may not form properly, or your sample will not react properly. Therefore, there are many possible qualitative testing issues that could occur.

3.     These tests cannot absolutely confirm the absence of an ion because in many cases you can not physically see the ion, so it is impossible to tell or judge the sample based on something that is not visible.

4.     If our tools were not properly cleaned, our samples could have had many qualitative testing problems. Incorrect chemicals would be mixed which could lead to improper reactions between chemicals or discoloration and many other issues.